China is a really interesting place that has had an incredible meteoric rise, but there are problems.
The Demographic collapse is wildly overstated. China has a workforce surplus and will have one for a long time, so there is no medium-term demographic issue. Instead, underproductive rural farmers will be proletarianized and turned into workers engaged in the economy.
This is a transition that was planned a really, really long time ago. The reason for the One Child policy being continued past the food insecurity times is moreso because there were too many farmers. And even today China has many more farmers than needed.